/Engine/Plugins/Experimental/TextToSpeech/Source/TextToSpeech/Public/TextToSpeechEngineSubsystem.h
Mutes a text to speech channel so no vocalized strings are audible on that channel. If the requested channel is already muted, nothing will happen.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category=TextToSpeech) void MuteChannel ( [FName](API\Runtime\Core\UObject\FName) InChannelId )